Most protocols that employ animal models for studying the development of alcoholic liver disease utilize the rat that is being administered ethanol as part of the diet. These models have provided much of the information we presently have on the mechanisms that contribute to development of liver damage associated with alcohol abuse. To date there are no animal models where voluntary ethanol consumption has led to irreversible liver damage; i.e., damage past the fatty liver stage. The studies proposed in this application are designed to determine if non-human primates that are self-administering ethanol will demonstrate liver pathology predictive of the development of alcoholic hepatitis and fibrosis. Eleven Macaca fascicularis monkeys will be given free access to ethanol in drinking water for 1 year. These animals have been previously trained to drink ethanol voluntarily and some have consumed up to 4g/kg/day, which is equivalent to 16 drinks a day by a human. The heavier drinkers averaged blood ethanol concentrations of 170 mg/dl in a previous protocol. In the proposed studies, light, moderate and heavy drinkers will be included, which are comprised of 6 females and 5 males. Evidence for liver damage will be sought by analyses of blood samples, which will include measurements of y-glutamyltransferase, aspartate and alanine transaminases, bilirubin, albumin, globulin and other blood components. Urinary concentrations of isoprostanes will be measured to screen for ethanol-related oxidative stress. Liver needle biopsy samples, taken every 3 months, will be examined by light and electron microscopy for indices of liver damage, such as hepatocyte ballooning, Mallory body formation, inflammation and fibrosis. lmmunohistochemical analyses will be implemented to measure levels of inflammation, apoptosis and stellate cell activation. The objectives of this study are 1) to determine if the self-administering M. fascicularis will develop liver pathology past the fatty liver stage and 2) to evaluate the efficacy of using blood and urine samples to follow development of alcoholic liver disease in an animal model.